Designed to check the amount of cylinder leakage in a 4-stroke engine. With an air source of 70 to 150 psi. this system will pressurize the cylinder with 60 psi. of air. Gauge will register the total percentage of leakage past the rings, head gasket, intake and exhaust valves. 10, 12, 14 & 18mm spark plug thread hoses, regulator and gauge included. Speeds up troubleshooting & helps to isolate bad components. Includes convenient carrying box